Jiang Taigong spent his youth failing, meat that spoiled, shops that folded, until his wife Ma left the bookworm. At seventy-two he was discovered by King Wen of Zhou, masterminded the overthrow of the Shang, and became Duke of Qi. When Ma returned begging reconciliation, he poured a basin of water on the ground: gather it up and I will take you back. She gathered mud. The scene produced the idiom fu shui nan shou, spilled water is hard to retrieve, for anything that cannot be undone. A Tang poem fixed the four characters; the Song broadened it beyond marriage.
English cries over spilled milk; Chinese pours the water deliberately. The difference is the whole story: the milk is an accident to grieve, the basin is a verdict to deliver. The idiom carries Jiang Taigong's fifty-year arc inside it, failure, abandonment, vindication, so saying it is never neutral: it implies someone once doubted, and the water is now on the ground.
The claim: the idiom's hidden premise is that most things in a life are retrievable, apologies, careers, kingdoms, so the truly irreversible earns a special word; in an age of version control and undelete, the category is collapsing, and fu shui nan shou may be the first idiom technology kills. Verdict: versions can be rolled back; reputations, trust, and seventy-two years cannot. The water still will not gather. The archive files it under laws that outlast their metaphors.
Is the idiom about water, or about the man who waited fifty years to pour it?